Joint optimization of bandwidth part, search space and connected mode discontinuous reception operation in 5G New Radio

ABSTRACT

Apparatuses, systems, and methods for a user equipment device (UE) to perform a method using a status change of a timer associated with a connected mode discontinuous reception (CDRX) communication session with a base station to trigger a switch from using a first bandwidth part (BWP) to a second BWP as the active BWP for the CDRX communication session. The timer may be an on-duration timer, an inactivity timer, or a retransmission timer. The UE may also alter a monitoring schedule of a physical downlink control channel (PDCCH) in response to detecting the status change of the timer. The second BWP may have a wider or narrower bandwidth than the first BWP, depending on the type of timer and the type of status change.

PRIORITY CLAIM

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/779,392, titled “Joint Optimization of Bandwidth Part, SearchSpace and Connected Mode Discontinuous Reception Operation in 5G NewRadio” and filed on Dec. 13, 2018, which is hereby incorporated byreference in its entirety, as though fully and completely set forthherein.

FIELD

The present application relates to wireless devices, and moreparticularly to apparatus, systems, and methods for a wireless device todynamically switch an active bandwidth part and monitoring protocolbased on timer activity.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. In recentyears, wireless devices such as smart phones and tablet computers havebecome increasingly sophisticated. In addition to supporting telephonecalls, many mobile devices now provide access to the internet, email,text messaging, and navigation using the global positioning system(GPS), and are capable of operating sophisticated applications thatutilize these functionalities.

Long Term Evolution (LTE) has become the technology of choice for themajority of wireless network operators worldwide, providing mobilebroadband data and high-speed Internet access to their subscriber base.LTE defines a number of downlink (DL) physical channels, categorized astransport or control channels, to carry information blocks received frommedia access control (MAC) and higher layers. LTE also defines a numberof physical layer channels for the uplink (UL).

A proposed next telecommunications standard moving beyond the currentInternational Mobile Telecommunications-Advanced (IMT-Advanced)Standards is called 5th generation mobile networks or 5th generationwireless systems, or 5G for short (otherwise known as 5G-NR for 5G NewRadio, also simply referred to as NR). 5G-NR proposes a higher capacityfor a higher density of mobile broadband users, also supportingdevice-to-device, ultra-reliable, and massive machine communications, aswell as lower latency and lower battery consumption, than current LTEstandards. Further, the 5G-NR standard may allow the available bandwidthused in communication between a base station and a UE to be divided intomultiple bandwidth parts (BWP). Consequently, efforts are being made inongoing developments of 5G-NR to take advantage of the flexibility inBWP allocation in order to further leverage power savings opportunities.According, improvements in the field are desirable.

SUMMARY

Embodiments relate to apparatuses, systems, and methods to constructdynamic hierarchical connected mode discontinuous reception (CDRX)sub-configurations for each of a plurality of bandwidth parts (BWPs) andto dynamically switch an active BWP based on timer activity.

In some embodiments, a UE may dynamically switch an active BWP and/or amonitoring schedule based on timer activity associated with a CDRXcommunications session.

The techniques described herein may be implemented in and/or used with anumber of different types of devices, including but not limited tocellular phones, tablet computers, wearable computing devices, portablemedia players, and any of various other computing devices.

This Summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present subject matter can be obtainedwhen the following detailed description of various embodiments isconsidered in conjunction with the following drawings, in which:

FIG. 1 illustrates an example wireless communication system according tosome embodiments;

FIG. 2 illustrates a base station (BS) in communication with a userequipment (UE) device according to some embodiments;

FIG. 3 illustrates an example block diagram of a UE according to someembodiments;

FIG. 4 illustrates an example block diagram of a BS according to someembodiments;

FIG. 5 is an illustration of transitioning between different active BWPsin response to timer activity, according to some embodiments;

FIG. 6 is a table illustrating two example connected mode discontinuousreception (CDRX) configurations for two different types of traffic,according to some embodiments;

FIG. 7 is a table illustrating two example BWP configurations differentBWP timer durations based on timer conditions, according to someembodiments;

FIG. 8 is a table illustrating two example BWP configurations differentsearch space configuration based on time conditions, according to someembodiments; and

FIG. 9 is a flowchart diagram illustrating a method for switching activeBWPs based on a status change of a timer, according to some embodiments.

While the features described herein may be susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and are herein described indetail. It should be understood, however, that the drawings and detaileddescription thereto are not intended to be limiting to the particularform disclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the subject matter as defined by the appended claims.

DETAILED DESCRIPTION Terms

The following is a glossary of terms used in this disclosure:

Memory Medium—Any of various types of non-transitory memory devices orstorage devices. The term “memory medium” is intended to include aninstallation medium, e.g., a CD-ROM, floppy disks, or tape device; acomputer system memory or random access memory such as DRAM, DDR RAM,SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash,magnetic media, e.g., a hard drive, or optical storage; registers, orother similar types of memory elements, etc. The memory medium mayinclude other types of non-transitory memory as well or combinationsthereof. In addition, the memory medium may be located in a firstcomputer system in which the programs are executed, or may be located ina second different computer system which connects to the first computersystem over a network, such as the Internet. In the latter instance, thesecond computer system may provide program instructions to the firstcomputer for execution. The term “memory medium” may include two or morememory mediums which may reside in different locations, e.g., indifferent computer systems that are connected over a network. The memorymedium may store program instructions (e.g., embodied as computerprograms) that may be executed by one or more processors.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Programmable Hardware Element—includes various hardware devicescomprising multiple programmable function blocks connected via aprogrammable interconnect. Examples include FPGAs (Field ProgrammableGate Arrays), PLDs (Programmable Logic Devices), FPOAs (FieldProgrammable Object Arrays), and CPLDs (Complex PLDs). The programmablefunction blocks may range from fine grained (combinatorial logic or lookup tables) to coarse grained (arithmetic logic units or processorcores). A programmable hardware element may also be referred to as“reconfigurable logic”.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

User Equipment (UE) (or “UE Device”)—any of various types of computersystems devices which are mobile or portable and which performs wirelesscommunications. Examples of UE devices include mobile telephones orsmart phones (e.g., iPhone™, Android™-based phones), portable gamingdevices (e.g., Nintendo DS™ Play Station Portable™, Gameboy Advance™,iPhone™), laptops, wearable devices (e.g. smart watch, smart glasses),PDAs, portable Internet devices, music players, data storage devices, orother handheld devices, etc. In general, the term “UE” or “UE device”can be broadly defined to encompass any electronic, computing, and/ortelecommunications device (or combination of devices) which is easilytransported by a user and capable of wireless communication.

Base Station—The term “Base Station” has the full breadth of itsordinary meaning, and at least includes a wireless communication stationinstalled at a fixed location and used to communicate as part of awireless telephone system or radio system.

Processing Element—refers to various elements or combinations ofelements that are capable of performing a function in a device, such asa user equipment or a cellular network device. Processing elements mayinclude, for example: processors and associated memory, portions orcircuits of individual processor cores, entire processor cores,processor arrays, circuits such as an ASIC (Application SpecificIntegrated Circuit), programmable hardware elements such as a fieldprogrammable gate array (FPGA), as well any of various combinations ofthe above.

Channel—a medium used to convey information from a sender (transmitter)to a receiver. It should be noted that since characteristics of the term“channel” may differ according to different wireless protocols, the term“channel” as used herein may be considered as being used in a mannerthat is consistent with the standard of the type of device withreference to which the term is used. In some standards, channel widthsmay be variable (e.g., depending on device capability, band conditions,etc.). For example, LTE may support scalable channel bandwidths from 1.4MHz to 20 MHz. In contrast, WLAN channels may be 22 MHz wide whileBluetooth channels may be 1 Mhz wide. Other protocols and standards mayinclude different definitions of channels. Furthermore, some standardsmay define and use multiple types of channels, e.g., different channelsfor uplink or downlink and/or different channels for different uses suchas data, control information, etc.

Band—The term “band” has the full breadth of its ordinary meaning, andat least includes a section of spectrum (e.g., radio frequency spectrum)in which channels are used or set aside for the same purpose.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

Approximately—refers to a value that is almost correct or exact. Forexample, approximately may refer to a value that is within 1 to 10percent of the exact (or desired) value. It should be noted, however,that the actual threshold value (or tolerance) may be applicationdependent. For example, in some embodiments, “approximately” may meanwithin 0.1% of some specified or desired value, while in various otherembodiments, the threshold may be, for example, 2%, 3%, 5%, and soforth, as desired or as required by the particular application.

Concurrent—refers to parallel execution or performance, where tasks,processes, or programs are performed in an at least partiallyoverlapping manner. For example, concurrency may be implemented using“strong” or strict parallelism, where tasks are performed (at leastpartially) in parallel on respective computational elements, or using“weak parallelism”, where the tasks are performed in an interleavedmanner, e.g., by time multiplexing of execution threads.

Various components may be described as “configured to” perform a task ortasks. In such contexts, “configured to” is a broad recitation generallymeaning “having structure that” performs the task or tasks duringoperation. As such, the component can be configured to perform the taskeven when the component is not currently performing that task (e.g., aset of electrical conductors may be configured to electrically connect amodule to another module, even when the two modules are not connected).In some contexts, “configured to” may be a broad recitation of structuregenerally meaning “having circuitry that” performs the task or tasksduring operation. As such, the component can be configured to performthe task even when the component is not currently on. In general, thecircuitry that forms the structure corresponding to “configured to” mayinclude hardware circuits.

Various components may be described as performing a task or tasks, forconvenience in the description. Such descriptions should be interpretedas including the phrase “configured to.” Reciting a component that isconfigured to perform one or more tasks is expressly intended not toinvoke 35 U.S.C. § 112(f) interpretation for that component.

FIGS. 1 and 2—Communication System

FIG. 1 illustrates a simplified example wireless communication system,according to some embodiments. It is noted that the system of FIG. 1 ismerely one example of a possible system, and that features of thisdisclosure may be implemented in any of various systems, as desired.

As shown, the example wireless communication system includes a basestation 102A which communicates over a transmission medium with one ormore user devices 106A, 106B, etc., through 106N. Each of the userdevices may be referred to herein as a “user equipment” (UE). Thus, theuser devices 106 are referred to as UEs or UE devices.

The base station (BS) 102A may be a base transceiver station (BTS) orcell site (a “cellular base station”), and may include hardware thatenables wireless communication with the UEs 106A through 106N.

The communication area (or coverage area) of the base station may bereferred to as a “cell.” The base station 102A and the UEs 106 may beconfigured to communicate over the transmission medium using any ofvarious radio access technologies (RATs), also referred to as wirelesscommunication technologies, or telecommunication standards, such as GSM,UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces),LTE, LTE-Advanced (LTE-A), 5G new radio (5G NR), HSPA, 3GPP2 CDMA2000(e.g., 1×RTT, 1×EV-DO, HRPD, eHRPD), etc. Note that if the base station102A is implemented in the context of LTE, it may alternately bereferred to as an ‘eNodeB’ or ‘eNB’. Note that if the base station 102Ais implemented in the context of 5G NR, it may alternately be referredto as ‘gNodeB’ or ‘gNB’.

As shown, the base station 102A may also be equipped to communicate witha network 100 (e.g., a core network of a cellular service provider, atelecommunication network such as a public switched telephone network(PSTN), and/or the Internet, among various possibilities). Thus, thebase station 102A may facilitate communication between the user devicesand/or between the user devices and the network 100. In particular, thecellular base station 102A may provide UEs 106 with varioustelecommunication capabilities, such as voice, SMS and/or data services.

Base station 102A and other similar base stations (such as base stations102B . . . 102N) operating according to the same or a different cellularcommunication standard may thus be provided as a network of cells, whichmay provide continuous or nearly continuous overlapping service to UEs106A-N and similar devices over a geographic area via one or morecellular communication standards.

Thus, while base station 102A may act as a “serving cell” for UEs 106A-Nas illustrated in FIG. 1, each UE 106 may also be capable of receivingsignals from (and possibly within communication range of) one or moreother cells (which might be provided by base stations 102B-N and/or anyother base stations), which may be referred to as “neighboring cells”.Such cells may also be capable of facilitating communication betweenuser devices and/or between user devices and the network 100. Such cellsmay include “macro” cells, “micro” cells, “pico” cells, and/or cellswhich provide any of various other granularities of service area size.For example, base stations 102A-B illustrated in FIG. 1 might be macrocells, while base station 102N might be a micro cell. Otherconfigurations are also possible.

In some embodiments, base station 102A may be a next generation basestation, e.g., a 5G New Radio (5G NR) base station, or “gNB”. In someembodiments, a gNB may be connected to a legacy evolved packet core(EPC) network and/or to a NR core (NRC) network. In addition, a gNB cellmay include one or more transition and reception points (TRPs). Inaddition, a UE capable of operating according to 5G NR may be connectedto one or more TRPs within one or more gNBs.

Note that a UE 106 may be capable of communicating using multiplewireless communication standards. For example, the UE 106 may beconfigured to communicate using a wireless networking (e.g., Wi-Fi)and/or peer-to-peer wireless communication protocol (e.g., Bluetooth,Wi-Fi peer-to-peer, etc.) in addition to at least one cellularcommunication protocol (e.g., GSM, UMTS (associated with, for example,WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2CDMA2000 (e.g., 1×RTT, 1×EV-DO, HRPD, eHRPD), etc.). The UE 106 may alsoor alternatively be configured to communicate using one or more globalnavigational satellite systems (GNSS, e.g., GPS or GLONASS), one or moremobile television broadcasting standards (e.g., ATSC-M/H or DVB-H),and/or any other wireless communication protocol, if desired. Othercombinations of wireless communication standards (including more thantwo wireless communication standards) are also possible.

FIG. 2 illustrates user equipment 106 (e.g., one of the devices 106Athrough 106N) in communication with a base station 102, according tosome embodiments. The UE 106 may be a device with cellular communicationcapability such as a mobile phone, a hand-held device, a computer or atablet, or virtually any type of wireless device.

The UE 106 may include a processor that is configured to execute programinstructions stored in memory. The UE 106 may perform any of the methodembodiments described herein by executing such stored instructions.Alternatively, or in addition, the UE 106 may include a programmablehardware element such as an FPGA (field-programmable gate array) that isconfigured to perform any of the method embodiments described herein, orany portion of any of the method embodiments described herein.

The UE 106 may include one or more antennas for communicating using oneor more wireless communication protocols or technologies. In someembodiments, the UE 106 may be configured to communicate using, forexample, CDMA2000 (1×RTT/1×EV-DO/HRPD/eHRPD) or LTE using a singleshared radio and/or GSM or LTE using the single shared radio. The sharedradio may couple to a single antenna, or may couple to multiple antennas(e.g., for MIMO) for performing wireless communications. In general, aradio may include any combination of a baseband processor, analog RFsignal processing circuitry (e.g., including filters, mixers,oscillators, amplifiers, etc.), or digital processing circuitry (e.g.,for digital modulation as well as other digital processing). Similarly,the radio may implement one or more receive and transmit chains usingthe aforementioned hardware. For example, the UE 106 may share one ormore parts of a receive and/or transmit chain between multiple wirelesscommunication technologies, such as those discussed above.

In some embodiments, the UE 106 may include separate transmit and/orreceive chains (e.g., including separate antennas and other radiocomponents) for each wireless communication protocol with which it isconfigured to communicate. As a further possibility, the UE 106 mayinclude one or more radios which are shared between multiple wirelesscommunication protocols, and one or more radios which are usedexclusively by a single wireless communication protocol. For example,the UE 106 might include a shared radio for communicating using eitherof LTE or 5G NR (or LTE or 1×RTT or LTE or GSM), and separate radios forcommunicating using each of Wi-Fi and Bluetooth. Other configurationsare also possible.

FIG. 3—Block Diagram of a UE

FIG. 3 illustrates an example simplified block diagram of acommunication device 106, according to some embodiments. It is notedthat the block diagram of the communication device of FIG. 3 is only oneexample of a possible communication device. According to embodiments,communication device 106 may be a user equipment (UE) device, a mobiledevice or mobile station, a wireless device or wireless station, adesktop computer or computing device, a mobile computing device (e.g., alaptop, notebook, or portable computing device), a tablet and/or acombination of devices, among other devices. As shown, the communicationdevice 106 may include a set of components 300 configured to performcore functions. For example, this set of components may be implementedas a system on chip (SOC), which may include portions for variouspurposes. Alternatively, this set of components 300 may be implementedas separate components or groups of components for the various purposes.The set of components 300 may be coupled (e.g., communicatively;directly or indirectly) to various other circuits of the communicationdevice 106.

For example, the communication device 106 may include various types ofmemory (e.g., including NAND flash 310), an input/output interface suchas connector I/F 320 (e.g., for connecting to a computer system; dock;charging station; input devices, such as a microphone, camera, keyboard;output devices, such as speakers; etc.), the display 360, which may beintegrated with or external to the communication device 106, andcellular communication circuitry 330 such as for 5G NR, LTE, GSM, etc.,and short to medium range wireless communication circuitry (e.g.,Bluetooth™ and WLAN circuitry). In some embodiments, communicationdevice 106 may include wired communication circuitry (not shown), suchas a network interface card, e.g., for Ethernet.

The cellular communication circuitry 330 may couple (e.g.,communicatively; directly or indirectly) to one or more antennas, suchas antenna 335 as shown. Alternatively, short to medium range wirelesscommunication circuitry may couple (e.g., communicatively; directly orindirectly) to the antenna 335. The short to medium range wirelesscommunication circuitry and/or cellular communication circuitry 330 mayinclude multiple receive chains and/or multiple transmit chains forreceiving and/or transmitting multiple spatial streams, such as in amultiple-input multiple output (MIMO) configuration.

In some embodiments, as further described below, cellular communicationcircuitry 330 may include dedicated receive chains (including and/orcoupled to, e.g., communicatively; directly or indirectly. dedicatedprocessors and/or radios) for multiple RATs (e.g., a first receive chainfor LTE and a second receive chain for 5G NR). In addition, in someembodiments, cellular communication circuitry 330 may include a singletransmit chain that may be switched between radios dedicated to specificRATs. For example, a first radio may be dedicated to a first RAT, e.g.,LTE, and may be in communication with a dedicated receive chain and atransmit chain shared with an additional radio, e.g., a second radiothat may be dedicated to a second RAT, e.g., 5G NR, and may be incommunication with a dedicated receive chain and the shared transmitchain.

The communication device 106 may also include and/or be configured foruse with one or more user interface elements. The user interfaceelements may include any of various elements, such as display 360 (whichmay be a touchscreen display), a keyboard (which may be a discretekeyboard or may be implemented as part of a touchscreen display), amouse, a microphone and/or speakers, one or more cameras, one or morebuttons, and/or any of various other elements capable of providinginformation to a user and/or receiving or interpreting user input.

The communication device 106 may further include one or more smart cardsthat include SIM (Subscriber Identity Module) functionality, such as oneor more UICC(s) (Universal Integrated Circuit Card(s)) cards.

As shown, the SOC 300 may include processor(s) 302, which may executeprogram instructions for the communication device 106 and displaycircuitry 304, which may perform graphics processing and provide displaysignals to the display 360. The processor(s) 302 may also be coupled tomemory management unit (MMU) 340, which may be configured to receiveaddresses from the processor(s) 302 and translate those addresses tolocations in memory (e.g., memory 306, read only memory (ROM) 350, NANDflash memory 310) and/or to other circuits or devices, such as thedisplay circuitry 304, short range wireless communication circuitry,cellular communication circuitry 330, connector I/F 320, and/or display360. The MMU 340 may be configured to perform memory protection and pagetable translation or set up. In some embodiments, the MMU 340 may beincluded as a portion of the processor(s) 302.

As noted above, the communication device 106 may be configured tocommunicate using wireless and/or wired communication circuitry. Thecommunication device 106 may be configured to perform a method includingperforming one or more of periodic beam quality measurements and/orevent based beam quality measurements, determining, based at least inpart on one or more of the periodic beam quality measurements and/or theevent based beam quality measurements, a recommended beam qualitymeasurement configuration, and transmitting, to a base station servingthe UE, the recommended beam quality measurement configuration. Inaddition, the UE may perform receiving, from the base station,instructions regarding the beam quality measurement configuration. Theinstructions may include instructions to activate, deactivate, and/ormodify at least one beam quality measurement configuration. In addition,the instructions may be based, at least in part, on the recommend beamquality measurement configuration.

As described herein, the communication device 106 may include hardwareand software components for implementing the above features forrecommending a beam quality measurement configuration. The processor 302of the communication device 106 may be configured to implement part orall of the features described herein, e.g., by executing programinstructions stored on a memory medium (e.g., a non-transitorycomputer-readable memory medium). Alternatively (or in addition),processor 302 may be configured as a programmable hardware element, suchas an FPGA (Field Programmable Gate Array), or as an ASIC (ApplicationSpecific Integrated Circuit). Alternatively (or in addition) theprocessor 302 of the communication device 106, in conjunction with oneor more of the other components 300, 304, 306, 310, 320, 330, 340, 350,360 may be configured to implement part or all of the features describedherein.

In addition, as described herein, processor 302 may include one or moreprocessing elements. Thus, processor 302 may include one or moreintegrated circuits (ICs) that are configured to perform the functionsof processor 302. In addition, each integrated circuit may includecircuitry (e.g., first circuitry, second circuitry, etc.) configured toperform the functions of processor(s) 302.

Further, as described herein, cellular communication circuitry 330 andshort range wireless communication circuitry may each include one ormore processing elements. In other words, one or more processingelements may be included in cellular communication circuitry 330 and,similarly, one or more processing elements may be included in shortrange wireless communication circuitry. Thus, cellular communicationcircuitry 330 may include one or more integrated circuits (ICs) that areconfigured to perform the functions of cellular communication circuitry330. In addition, each integrated circuit may include circuitry (e.g.,first circuitry, second circuitry, etc.) configured to perform thefunctions of cellular communication circuitry 330. Similarly, the shortrange wireless communication circuitry may include one or more ICs thatare configured to perform the functions of short range wirelesscommunication circuitry. In addition, each integrated circuit mayinclude circuitry (e.g., first circuitry, second circuitry, etc.)configured to perform the functions of short range wirelesscommunication circuitry.

FIG. 4—Block Diagram of a Base Station

FIG. 4 illustrates an example block diagram of a base station 102,according to some embodiments. It is noted that the base station of FIG.4 is merely one example of a possible base station. As shown, the basestation 102 may include processor(s) 404 which may execute programinstructions for the base station 102. The processor(s) 404 may also becoupled to memory management unit (MMU) 440, which may be configured toreceive addresses from the processor(s) 404 and translate thoseaddresses to locations in memory (e.g., memory 460 and read only memory(ROM) 450) or to other circuits or devices.

The base station 102 may include at least one network port 470. Thenetwork port 470 may be configured to couple to a telephone network andprovide a plurality of devices, such as UE devices 106, access to thetelephone network as described above in FIGS. 1 and 2.

The network port 470 (or an additional network port) may also oralternatively be configured to couple to a cellular network, e.g., acore network of a cellular service provider. The core network mayprovide mobility related services and/or other services to a pluralityof devices, such as UE devices 106. In some cases, the network port 470may couple to a telephone network via the core network, and/or the corenetwork may provide a telephone network (e.g., among other UE devicesserviced by the cellular service provider).

In some embodiments, base station 102 may be a next generation basestation, e.g., a 5G New Radio (5G NR) base station, or “gNB”. In suchembodiments, base station 102 may be connected to a legacy evolvedpacket core (EPC) network and/or to a NR core (NRC) network. Inaddition, base station 102 may be considered a 5G NR cell and mayinclude one or more transition and reception points (TRPs). In addition,a UE capable of operating according to 5G NR may be connected to one ormore TRPs within one or more gNB s.

The base station 102 may include at least one antenna 434, and possiblymultiple antennas. The at least one antenna 434 may be configured tooperate as a wireless transceiver and may be further configured tocommunicate with UE devices 106 via radio 430. The antenna 434communicates with the radio 430 via communication chain 432.Communication chain 432 may be a receive chain, a transmit chain orboth. The radio 430 may be configured to communicate via variouswireless communication standards, including, but not limited to, 5G NR,LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

The base station 102 may be configured to communicate wirelessly usingmultiple wireless communication standards. In some instances, the basestation 102 may include multiple radios, which may enable the basestation 102 to communicate according to multiple wireless communicationtechnologies. For example, as one possibility, the base station 102 mayinclude an LTE radio for performing communication according to LTE aswell as a 5G NR radio for performing communication according to 5G NR.In such a case, the base station 102 may be capable of operating as bothan LTE base station and a 5G NR base station. As another possibility,the base station 102 may include a multi-mode radio which is capable ofperforming communications according to any of multiple wirelesscommunication technologies (e.g., 5G NR and Wi-Fi, LTE and Wi-Fi, LTEand UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

As described further subsequently herein, the BS 102 may includehardware and software components for implementing or supportingimplementation of features described herein. The processor 404 of thebase station 102 may be configured to implement or supportimplementation of part or all of the methods described herein, e.g., byexecuting program instructions stored on a memory medium (e.g., anon-transitory computer-readable memory medium). Alternatively, theprocessor 404 may be configured as a programmable hardware element, suchas an FPGA (Field Programmable Gate Array), or as an ASIC (ApplicationSpecific Integrated Circuit), or a combination thereof. Alternatively(or in addition) the processor 404 of the BS 102, in conjunction withone or more of the other components 430, 432, 434, 440, 450, 460, 470may be configured to implement or support implementation of part or allof the features described herein.

In addition, as described herein, processor(s) 404 may be comprised ofone or more processing elements. In other words, one or more processingelements may be included in processor(s) 404. Thus, processor(s) 404 mayinclude one or more integrated circuits (ICs) that are configured toperform the functions of processor(s) 404. In addition, each integratedcircuit may include circuitry (e.g., first circuitry, second circuitry,etc.) configured to perform the functions of processor(s) 404.

Further, as described herein, radio 430 may be comprised of one or moreprocessing elements. In other words, one or more processing elements maybe included in radio 430. Thus, radio 430 may include one or moreintegrated circuits (ICs) that are configured to perform the functionsof radio 430. In addition, each integrated circuit may include circuitry(e.g., first circuitry, second circuitry, etc.) configured to performthe functions of radio 430.

Bandwidth Parts in 5G NR

It is anticipated that 5G NR may partition the available bandwidth for acommunication session between a UE and a gNB into multiple bandwidthparts (BWPs). Each of the BWPs may occupy a different bandwidth, andeach BWP may overlap or not overlap in frequency with other BWPs.Additionally, each BWP may operate according to a particular numerology,which may differ between BWPs to offer more diverse communicationopportunities to the UE. At any given time, only one of the BWPs may beactively used at a time for each of uplink (UL) and downlink (DL), andthe BWP being used may be referred to as the active BWP (e.g., there maybe a single active UL BWP and a single active DL BWP). The active BWPmay switch over time, and the switching between active BWPs may bedirected by downlink control information (DCI) messages, and/or it maybe based on a timer. For example, when a UE has data to be transmitted,DCI received from the gNB may direct the UE to use a particular BWP asthe active BWP for the data transmission. In some embodiments, the UEmay switch back to a default active BWP once a timer expires. Forexample, the UE may initiate a timer upon switching to an active BWP,and the timer may reset after receiving/transmitting DL/UL data on theBWP. Upon expiration of a timer (e.g., if the timer expires and data hasnot been received or transmitted on the BWP), the UE may switch toanother BWP, such as the default BWP. Advantageously, misalignment maybe prevented through employment of a timer to switch BWPs. Additionallyor alternatively, embodiments herein describe devices and methods forutilizing RRC-based signaling and/or CDRX timers to switch betweenactive BWPs.

When conducting PDCCH grant monitoring, it may be desirable for a UE tooperate at the minimum bandwidth BWP that is able to accomplish PDCCHgrant monitoring, to save power. It is anticipated that up to 4 BWPs maybe configured for 5G NR, and the particular choice of an active BWP mayvary according to different specific implementations.

A UE may supply feedback for the active BWP in a preference andbeamforming report, but the UE may not supply feedback for inactiveBWPs. For example, the UE may not be required/expected to measure/reportquality of BWPs that are configured but not yet activated. However, a UEmay be expected to perform channel state information (CSI) measurementswithin its active downlink (DL) BWP.

In some embodiments, a gNB may switch a UE to an active BWP to conductradio measurements, such as a channel state information reference signal(CSI-RS) on downlink (DL) and/or a sounding reference signal (SRS) onuplink (UL). In general, scheduling these measurements may requireadditional messaging and power drain. Autonomous measurement by a UE onother configured but non-active BWPs may be difficult and/or notfeasible given that the UE may not be informed of CSI-RS scheduling onthe particular BWP to be measured, such that it may be advantageous forthe network to coordinate the measurements.

In some embodiments, hybrid automatic repeat request (HARQ) signalingmay be supported through a BWP transition. For example, when a UE'sactive BWP is switched, a HARQ retransmission may occur across BWPs. Inother words, a HARQ retransmission may occur on a BWP that was recentlyswitched to active based on an earlier transmission on a differentactive BWP.

Even though channel quality indicators (CQIs), beamforming, and SRS maybe reported based on the current active BWP, the measurements may leadto inaccuracies if the active BWP is switched to other active BWPs fordata transmission, and the measurements are not updated with sufficientfrequency (i.e., if measurements have not been performed since theactive BWP was switched). Current implementations may use an outer loopmethod whereby the gNB may not know the CQI of a particular active BWP,but may probe different transmission parameters (e.g. differentfrequencies or other parameters such as different modulation codingschemes (MCS) and/or different transport block sizes (TBS)) to determinewhich parameters give the UE a higher throughput. However, these outerloop methods may take a significant amount of time to converge, therebyincreasing network latency.

Some embodiments herein present a systematic design to coordinate activeBWP switching for data transmission and channel measurements to reduceoverhead on the network and at the UE and gNB.

Control Resource Set (CORESET) and Search Space

In 5G NR, a Control Resource Set (CORESET) may be defined as a set ofresource element groups (REGs) with one or more symbol durations under agiven numerology within which a UE may attempt to blindly decodedownlink control information. In the time domain, a CORESET may have 1,2, or 3 contiguous OFDM symbols, and a CORESET may be contiguous ornon-contiguous in the frequency domain.

It is anticipated that up to three CORESETs may be configured for a BWPin a cell for a UE under 5G NR. Multiple CORESETs may be overlapped infrequency and time for a UE, and multiple search spaces may beassociated with a CORESET. In a CORESET, different search spaces (e.g.,a common search space and a UE-specific search space) may have differentperiodicities for a UE to monitor.

The set of PDCCH candidates that are monitored by a UE may be defined interms of PDCCH search space sets. A search space may define a set ofaggregation levels (ALs), a number of PDCCH candidates for each AL,PDCCH monitoring occasions, and/or an RNTI or DCI format to bemonitored. As one example, Type 0-PDCCH to Type 3-PDCCH may be used fora common search space, and a UE-specific search space set may beconfigured by SearchSpace in PDCCH-Config withsearchSpaceType=UE-Specific for DCI formats with CRC scrambled byC-RNTI, or CS-RNTI(s).

Each configured DL BWP may include at least one CORESET with aUE-specific search space. As described in greater detail below, the BWPconfigured as the active BWP, the CORESET, and the search spaceconfigured for a UE may be dynamically determined based on CDRX timeractivity.

BWP Activation Based on Timer Activity

In LTE, the bandwidth a UE operates at is typically cell-specificallyconfigured or RRC configured. Additionally, the UE may be required tomonitor the PDCCH either continuously or according to a CDRXsemi-statically configured by RRC protocols. Accordingly, in LTE it maynot be possible to dynamically adjust the operation bandwidth and PDCCHmonitoring periodicity/pattern, which may result in less than optimalpower efficiency in dynamic traffic conditions.

In contrast, it is anticipated that in 5G NR, BWPs may each beassociated with a different bandwidth and numerology, and CORESET/searchspace sets may each be associated with a different PDCCH monitoringperiodicity. Therefore, by switching BWPs a UE may dynamically adapt tochanging traffic conditions. However, switching the active BWP, CORESETand/or search space set may often incur delays and may requireadditional control resources from the gNB to implement.

To address these and other concerns, embodiments herein utilizing timerstatus changes related to a CDRX communication session as a proxy todetermine when to change active BWPs, CORESETs, and/or search spacesets. CDRX is expected to be supported in 5G NR, and pre-existing timeractivity related to an ongoing CDRX communication session may beutilized to time switches between active BWPs and search monitoringconfigurations. For example, the gNB and the UE may be time-alignedbased on the status of different timers in CDRX, and the timers maycapture traffic dynamics to some extent and thus may be used to triggerBWP/search space adaptation to reduce UE power consumption and latency.

In some embodiments, CDRX timers and BWP/CORESET/search spaceconfigurations may be jointly coordinated according to differentconfigurations for different types of data traffic. For example,depending on the type of data traffic utilized in the CDRX communicationsession, different configurations for altering BWPs, CORESETs, and/orsearch space sets based on timer status changes may be implemented.

FIG. 5—Switching Active BWP Based CDRX Timer Activity

FIG. 5 is a schematic diagram illustrating an autonomous method forswitching the active BWP based on CDRX timer activity. FIG. 5 isintended to illustrate one particular example, and is not intended to belimiting to the disclosure as a whole. In various embodiments, the UEand gNB may autonomously switch one or more of the active BWP, CORESETand search space upon different status changes to various CDRX timers.The triggered switch or adjustment may result in at least a change ofbandwidth, or PDCCH monitoring periodicity or duration. Status changesto different CDRX timers may capture traffic dynamics to some extent andmay be used to adjust PDCCH monitoring behavior.

FIG. 5 illustrates three types of timers associated with a CDRXcommunication session. The on-duration timer may be initiated when aCDRX communication session is initiated, and upon expiration of theon-duration timer, the UE may be triggered to go to sleep (i.e., toenter a DRX sleep state) if no other timer is running upon expiration ofthe on-duration timer. The inactivity timer may be triggered to initiateeach time a new grant is received, and may be refreshed upon each newgrant. Thus, expiration of the inactivity timer may indicate that no newgrant has been received during the expiry period of the inactivitytimer, suggesting that the UE may not expect to receive many new grantsin the near future. Finally, the retransmission timer may initiate whena DL grant is received but reception has failed. The retransmissiontimer may set a period of time to wait for a retransmission of thefailed DL grant.

In the example illustrated in FIG. 5, the UE may be triggered to utilizea medium bandwidth BWP (BWP1) when an on-duration timer is initiated. Insome embodiments, the periodicity associated with PDCCH search spacemonitoring may be continuous while using BWP1 as the active BWP.

As illustrated, when the inactivity timer starts (for example, this mayoccur when the UE detects a new PDSCH/PUSCH grant or the gNB sends newgrants), the UE may automatically switch the active BWP to BWP2, whichhas a wider bandwidth than BWP1 and may have similar or differentperiodicity, to accommodate possible upcoming traffic related to theinitiated inactivity timer.

Upon expiration of the inactivity timer, the UE may autonomously switchto a third active BWP (BWP3) with a narrow bandwidth, with similar ordifferent PDCCH monitoring periodicity. For example, expiration of theinactivity timer may be correlated with a slowing down of data traffic,such that the UE may not need to utilize the wide bandwidth of BWP2. TheUE may further base the decision to switch to BWP3 as the active BWPbased on a determination that, upon expiration of the inactivity timer,the only currently pending timer associated with the CDRX connection isa retransmission timer. For example, because only the retransmissiontimer is still running, the UE may likely only be expecting aretransmission packet (e.g., with narrow bandwidth requirements), sothat the UE and the gNB may preserve energy resources by switching tothe narrowband BWP3.

Finally, upon expiration of the retransmission timer, if no timers areactive with respect to the CDRX communication session, the UE may entera DRX sleep state to preserve power, where the UE does not have anactive BWP in the DRX sleep state.

Note that each of BWP1, BWP2, and BWP3 are illustrated schematically inFIG. 5, where the height of each BWP is indicative of the bandwidth ofthe BWP. However, each of the three BWPs may have the same or separatecenter-band frequencies, and may reside at overlapping ornon-overlapping frequency ranges, according to various embodiments.

FIG. 6—Conditions for Transitioning Between CDRX Configurations

FIG. 6 is a table illustrating two example CDRX configurations fortransitioning between different active BWPs and PDCCH monitoringprotocols depending on timer trigger conditions, for two different typesof data traffic. For each CDRX configuration, at least one UE-specificsearch space may be attached to a CORESET in a preferable BWP.

The UE may autonomously switch between different active BWPs dependingon the state of various CDRX timers. A delay that may be incurred whileswitching between active BWPs may be accounted for through a predefinedvalue known to both the gNB and the UE.

As illustrated in FIG. 6, a first CDRX configuration (CDRXconfiguration 1) may be used for video and enhanced mobile broadband(eMBB) data traffic. For CDRX configuration 1, a UE may be triggered touse BWP1 as the active BWP when the on-duration timer is running but noother CDRX timer is running, where BWP1 has a 10 MHz bandwidth andcontinuously monitors the PDCCH. In CDRX configuration 1, when both theon-duration timer and the inactivity timer are running, the UE mayswitch to BWP2, with a wideband 100 MHz bandwidth and where the UEperiodically monitors the PDCCH with a first predetermined period.Finally, if both the on-duration timer and the inactivity timer are notrunning (e.g., if they have both expired) and only the retransmissiontimer is running, the UE may use BWP3 as the active BWP with a verynarrowband 5 MHz bandwidth and where the UE periodically monitors thePDCCH with a second predetermined period.

As further illustrated in FIG. 6, a second CDRX configuration (CDRXconfiguration 2) may be used for voice-over LTE (VoLTE) and/or otherdelay sensitive traffic types. As illustrated, the same timer triggersmay be used to select three different BWPs to use as the active BWP,with different configurations for continuous and/or periodic PDCCHmonitoring, as desired. FIG. 6 is intended for illustrative purposes,and is not intended to limit the scope of the described embodiments inany way. For example, further types of data traffic may be configuredwith additional CDRX configurations, where different types of BWPsand/or PDDCH monitoring schedules may be employed for different timerstatus change triggers, as desired. Alternatively, in some embodiments,timer status change triggers may cause the UE to keep the same BWP, butthe search space and/or PDCCH monitoring schedule may be switchedautonomously.

FIG. 7—Conditions for Switching Bandwidth Part Timers

FIG. 7 is a table illustrating two example BWPs that may be configuredwith a customized timer depending on CDRX timer conditions, according tosome embodiments. In some embodiments, a timer may be configured for afirst BWP whereby, when the timer expires after the first BWP has beenconfigured as the active BWP, the UE may automatically switch from thefirst BWP to a default BWP as the active BWP. In other words, BWPs maybe configured to activate for a predetermined duration of time, and adefault BWP may be reactivated upon expiration of this duration of time.In some embodiments, the default BWP may be a narrow-band BWP that ispreferable for low traffic conditions.

In these embodiments, the first BWP may be configured with a differentBWP timer duration depending on the prevailing CDRX timer triggerconditions that exist when the first BWP is activated. The UE mayautomatically select the appropriate BWP timer duration while activatinga BWP depending on the CDRX timer conditions. Advantageously, theseembodiments may add flexibility to BWP activation to adapt to dynamictraffic patterns and conditions.

As illustrated, for a first BWP (BWP 1), the presence of an activelyrunning on-duration timer but neither an inactivity timer nor aretransmission timer may result in BWP 1 utilizing a 10 slot BWP timer.Alternatively, if both the on-duration timer and the inactivity timerare actively running, BWP may utilize a lengthened BWP timer with a 20slot duration.

The lower half of the table illustrated in FIG. 7 shows an alternativeembodiment for configuring a second BWP (BWP 2) with a set of threetimer durations. In the illustrated embodiment, initiation of anon-duration timer while neither an inactivity timer or a retransmissiontimer are running may cause the device to configure BWP 2 as the activeBWP with a first timer duration of 4 slots. The duration of 4 slots ispresented as an example, and more broadly the timer duration may beselected to be at least as long as the duration of the on-durationtimer. For example, it may be desirable for BWP 2 to remain the activeBWP as long as the on-duration timer is still running, such that thefirst BWP timer may be set to a duration equal to or slightly longerthan the on-duration timer. In other words, the first BWP timer durationmay be selected based on the on-duration timer duration.

If the device detects that both the on-duration timer and the inactivitytimer have been initiated (e.g., if the on-duration timer was running,and the device detects that the inactivity timer has additionally beeninitiated) while the retransmission timer is not running, the device mayselect a second BWP timer duration for BWP 2 (e.g., a duration of 10slots in the illustrated example). While a duration of 10 slots isselected as one example, more broadly, the second BWP timer duration maybe selected to be longer than the first BWP duration to accommodateupcoming traffic and allow scheduling flexibility.

Finally, if the device detects that neither the on-duration timer or theinactivity timer are running but the retransmission timer has beeninitiated, a third BWP timer duration may be selected for BWP 2 (e.g., aduration of 10 slots in the illustrated example). While a duration of 10slots is selected as one example, more broadly, the third BWP timerduration may be selected to be equal to or slightly greater than theduration of the retransmission timer. In other words, the third BWPtimer duration may be selected based on the retransmission timerduration.

Note that these embodiments may exist concurrently with otherembodiments described herein. For example, during a particular CDRXtimer condition of the table illustrated in FIG. 6 (i.e., a particularrow in the table of FIG. 6), the UE may switch to the indicated BWP(e.g., BWP1, BWP2, or BWP3) according to the timer duration indicated inFIG. 7.

FIG. 8—Conditions for Switching Search Space Sets

FIG. 8 is a table illustrating two example BWPs that may be configuredto utilize different search space configurations (e.g., different searchspace sets) depending on CDRX timer conditions, according to someembodiments. Different search space sets may implement one or morecustomized parameters for performing physical downlink control channel(PDCCH) monitoring, such as a monitoring periodicity, a PDCCH monitoringpattern (e.g., a number and/or location of monitoring symbols within aslot), a number of PDCCH candidates per control channel element (CCE)aggregation level L (e.g., the aggregation level may be 1, 2, 4, or 8,in some embodiments), and/or a search space type (e.g., whether thesearch space is a common search space set or a UE-specific search spaceset).

In some embodiments, if the CDRX timer activity suggests that the UE isexperiencing light traffic (e.g., if neither the inactivity timer northe retransmission timer are running), a UE may be able to save power byutilizing a BWP with a search space set that incorporates power savingparameters. For example, in response to determining that neither theinactivity timer nor the retransmission timer are running, the UE mayactivate BWP 1 with search space set 1, where search space set 1utilizes one or more power saving parameters, such as a lower monitoringbandwidth, a longer monitoring periodicity, a more sparse PDCCHmonitoring pattern, a lower number of PDCCH candidates per CCEaggregation level, and/or a search space type with lower powerconsumption.

Alternatively, if the CDRX timer activity suggests that the UE isexperiencing heavy traffic (e.g., if the inactivity timer is running),the UE may activate a BWP with search space set 2 that implementsenhanced monitoring parameters. For example, search space set 2 mayutilize an expanded search space to facilitate gNB schedulingflexibility. Search space set 2 may additionally or alternativelyutilize one or more of a shorter monitoring periodicity, a more densePDCCH monitoring pattern, a larger number of PDCCH candidates per CCEaggregation level, and/or a higher power search space type with higherpower consumption.

As further illustrated in FIG. 8, BWP 2 may utilize three differenttypes of search space set, depending on the CDRX timer status. Asillustrated, an additional search space set 3 may be utilized whenneither the on-duration timer nor the inactivity timer is running, butthe retransmission timer is running. Search space set 3 may haveintermediate power consumption between search space sets 1 and 2, insome embodiments.

Association Between Spatial Domain and CDRX/BWP Timers

In some embodiments, CDRX and/or BWP timer conditions may be utilized togovern spatial antenna parameters of a UE device. For example, sinceCDRX timer status may be used as a proxy for dynamic aspects of traffic(e.g., heavy vs. light traffic), CDRX timer status information may beused to adapt spatial domain operation of the UE, including one or moreof a number of antennas used for reception, a number of beams used forperforming sweeps and/or monitoring (e.g., synchronization signal block(SSB) beams or channel state information (CSI-RS) beams, among otherpossibilities), and/or a frequency of reporting channel conditions tothe base station (e.g., channel quality indicators (CQIs), precodingmatrix indicators (PMIs), and/or rank indicators (RI) among otherpossibilities).

Advantageously, the measurement frequency, reporting frequency, and/orMIMO capability may be reduced when the traffic is low as inferred fromCDRX timers, in some embodiments.

Autonomous Switching in 5G NR UL HARQ Monitoring

The following paragraphs describe example embodiments where utilizingCDRX timer status triggers to switch active BWPs and/or monitoringschedules may be used to improve HARQ monitoring performance in a 5G NRcommunication system.

In LTE, when a UE is configured with CDRX, it may enter a DRX sleepstate when, for example, one or more of an on-duration, inactivity, orretransmission timer expires. If a pending PUSCH message is awaiting anacknowledgment message, the UE may only need to wake up during aspecific subframe to monitor a Physical Channel Hybrid Automatic RepeatRequest (HARQ) Indicator Channel (PHICH) for an acknowledgment message,and the subframes may be periodically spaced a predetermined distanceapart (e.g., 8 ms or another duration of time apart).

In contrast, in 5G NR, it is anticipated that the PHICH may be removedand UL HARQ messaging may be asynchronous. In downlink controlinformation (DCI) format 0_0 and 0_1 for PUSCH scheduling, 4 bits of aHARQ process may be present to support asynchronous UL HARQ. Because thetimeline in 5G NR for UL for frequency division duplexing (FDD) and/ortime division duplexing (TDD) communications may be dynamicallyconfigured, the synchronous HARQ protocol used in LTE may not beeffective for 5G NR. To accommodate an asynchronous UL HARQ protocol in5G NR, in some embodiments New Data Indicator (NDI) toggling may be usedto identify new UL data.

In a typical 5G NR scenario, when a UE is engaged in a DRX connection,the UE may wait for the next on-duration timer to be initiated beforereceiving a PDCCH that may carry UL HARQ information. However, this maycause an undesirable delay as, for one particular example, the CDRXperiodicity may be configured as 40 ms and the next on-duration timermay not start until approximately 30 ms later. Alternatively, the UE maycontinuously monitor for HARQ messaging until a UL HARQ timer expired,but continuous monitoring consumes higher power than synchronouslymonitoring in a periodic manner as is typically done in LTE.Accordingly, the power consumption and/or delay incurred to monitor ULHARQ in NR may be much higher than in LTE.

To address these and other concerns, embodiments herein describe methodsand devices whereby the UE may save power through early terminationand/or reducing the amount of UL HARQ monitoring. This may be beneficialin a CDRX scenario to reduce UL HARQ monitoring in between DRX wakeups,which may allow the UE to enter a lower power state during CDRX sleep.Utilizing a special UL BWP configuration to monitor UL HARQ/grants forparticular traffic types (e.g., VoLTE) may reduce UE power consumptionand extend battery life.

As one particular example, a UE may be configured with a CDRX with denseperiodicity for monitoring the PDCCH (e.g., continuously) and/or a BWPwith a large bandwidth. The UE may transmit a PUSCH and subsequently, aninactivity timer may expire (e.g., indicating that the wideband BWP mayno longer be necessary, as traffic volume has become sufficiently sparsesuch that the inactivity timer has expired). The expiration of theinactivity timer may cause the UE to transition to a different activeBWP. If the previous transmitted PUSCH has not yet received anacknowledgment message (ACK) when the timer expires, the UE mayautomatically switch to another BWP with longer periodicity to reducethe time for HARQ monitoring. Upon reception of an ACK on this specialBWP, the UE may subsequently enter a DRX sleep state to preserve power,and deactivate the special BWP. Finally, when a next on-duration timeris initiated, the UE may resume communications with the default BWP asthe active BWP.

FIG. 9—Timer-based Switching of Active BWP

FIG. 9 is a flow chart diagram illustrating a method utilizing statuschanges to one or more timers associated with a CDRX communicationsession to direct switching between active BWPs, CORESETs, and/or searchspace sets, according to some embodiments. The scheme shown in FIG. 9may be used in conjunction with any of the computer systems or devicesshown in the above Figures, among other devices. In various embodiments,some of the elements of the scheme shown may be performed concurrently,in a different order than shown, or may be omitted. Additional elementsmay also be performed as desired. As shown, the scheme may operate asfollows.

At 902, a user equipment device (UE) communicates with a base stationusing a first BWP as an active BWP in a CDRX communication session. Insome embodiments, communicating with the base station using the firstBWP as the active BWP in the CDRX communication session is performed inresponse to detection by the UE of initiation of an on-duration timer.For example, initiation of the on-duration timer may trigger the UE toestablish the CDRX communication session with the base station using thefirst BWP as the active BWP.

At 904, the UE may determine that a first timer associated with the CDRXcommunication session has experienced a status change. In variousembodiments, the first timer may be an inactivity timer, an on-durationtimer, or a retransmission timer, among other possibilities. The statuschange may be either the initiation or expiration of the first timer, insome embodiments.

At 906, the UE may switch the active BWP from the first BWP to a secondBWP based at least in part on the determination that the first timer hasexperienced the status change, where the second BWP has a differentbandwidth than the first BWP. In some embodiments, in addition to oralternatively to switching from a first to a second active BWP, the UEmay switch the schedule and/or duration for monitoring a physicaldownlink control channel (PDCCH) upon determining that the first timerhas experienced the status change. For example, the UE may continuouslymonitor the PDCCH while the first BWP is the active BWP, and may switchfrom continuously monitoring the PDCCH to periodically monitoring thePDCCH based at least in part on the determination that the first timerhas experienced the status change. Additionally or alternatively, the UEmay switch one or more of a control resource set (CORESET) and a searchspace associated with the CDRX communication session based at least inpart on the determination that the first timer has experienced thestatus change. In some embodiments, switching one or more of the CORESETand the search space associated with the CDRX communication sessioncomprises switching one or more of the monitoring periodicity andduration of the PDCCH.

Advantageously, the UE and the base station may be time synchronizedthrough the timer activity. For example, one or more timers running atthe UE may additionally be synchronously running at the base station,such that the base station may also detect a status change to the timer.Accordingly, when the UE switches the active BWP from the first BWP tothe second BWP, the base station may also switch from communicating withthe UE with the first BWP to the second BWP. For example, a protocoltable such as those illustrated in FIGS. 6-8 may be known to both thebase station and the UE, such that both the base station and the UE canswitch in a coordinated manner between active BWPs and/or PDCCHmonitoring schedules or duration based on a timer status change.

For embodiments where the first timer is an inactivity timer and thestatus change is an initiation of the inactivity timer, the second BWPmay have a larger bandwidth than the first BWP. For example, theinitiation of the inactivity timer may suggest a high likelihood ofheavier upcoming data traffic, such that the UE may benefit fromtransitioning to a wider bandwidth BWP. Additionally or alternatively,the initiation of the inactivity timer may suggest that periodicmonitoring of the PDCCH may be more effective and power efficient thancontinuously monitoring the PDCCH, and the UE may thereby switch itsPDCCH monitoring schedule.

For embodiments where the first timer is an inactivity timer and thestatus change is an expiration of the inactivity timer, the second BWPmay have a smaller bandwidth than the first BWP. For example, theexpiration of the inactivity timer may suggest a high likelihood of areduction in upcoming data traffic volume, such that the UE may preservepower by transitioning to a narrower bandwidth BWP, as the wideband BWPmay be no longer necessary. In these embodiments, the UE may furtherdetermine that a retransmission timer is running when the inactivitytimer expires, and switching the active BWP from the first BWP to thesecond BWP is further based at least in part on the determination thatthe retransmission timer is running when the inactivity timer expires.Alternatively, if the UE determines that the retransmission timer is notrunning when the inactivity timer expires (e.g., if the UE determinesthat no timer is running when the inactivity timer expires), the UE mayenter a DRX sleep state where no active BWP is configured and the UEenters a power saving mode.

In some embodiments, subsequent to switching the active BWP from thefirst BWP to the second BWP, the UE may determine that a second timerassociated with the CDRX communication session has expired. In theseembodiments, the UE may enter a DRX sleep state based at least in parton the determination that the second timer has expired. For example,upon expiration of the first timer, a second timer may have still beenrunning, implying that the UE may likely experience reduced data trafficsuch that a narrowband active BWP is sufficient (e.g., the UE may stillbe awaiting a retransmission). Upon expiration of the second timer, theUE may conclude that no further data traffic is anticipated, and mayenter a sleep state to save power.

In some embodiments, the UE may continue the CDRX communication sessionafter switching to the second BWP as the active BWP. For example, whilecommunicating with the base station using the first BWP as the activeBWP, the UE may transmit an uplink message to the base station andmonitor for a hybrid automatic repeat request (HARQ) message associatedwith the transmitted uplink message. In this example, it is possiblethat the UE detects the status change to the first timer beforereceiving the HARQ message, such that said switching the active BWP fromthe first BWP to the second BWP occurs before the UE receives the HARQmessage. In these embodiments, subsequent to switching the active BWPfrom the first BWP to the second BWP, the UE may monitor for the HARQmessage using the second BWP.

Alternative Proposal for HARQ Monitoring in NR

In some embodiments, the gNB may support sending DCI messaging toterminate an UL HARQ process early. For example, a special DCI or abit-field in DL/UL DCI may be used to inform the UE that a previous HARQis complete. In one example, such DCI messaging may be an UL DCI withNDI toggled but zero resource allocation. For example, toggling the NDIwith zero resource allocation may be utilized to indicate that the HARQprocess is complete. The DCI may be triggered when the gNB identifiesthat the UE is in a DRX state and is pending on an UL HARQ monitoringprocess, in some embodiments.

It is well understood that the use of personally identifiableinformation should follow privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining the privacy of users. In particular,personally identifiable information data should be managed and handledso as to minimize risks of unintentional or unauthorized access or use,and the nature of authorized use should be clearly indicated to users.

Embodiments of the present disclosure may be realized in any of variousforms. For example, some embodiments may be realized as acomputer-implemented method, a computer-readable memory medium, or acomputer system. Other embodiments may be realized using one or morecustom-designed hardware devices such as ASICs. Still other embodimentsmay be realized using one or more programmable hardware elements such asFPGAs.

In some embodiments, a non-transitory computer-readable memory mediummay be configured so that it stores program instructions and/or data,where the program instructions, if executed by a computer system, causethe computer system to perform a method, e.g., any of the methodembodiments described herein, or, any combination of the methodembodiments described herein, or, any subset of any of the methodembodiments described herein, or, any combination of such subsets.

In some embodiments, a device (e.g., a UE 106) may be configured toinclude a processor (or a set of processors) and a memory medium, wherethe memory medium stores program instructions, where the processor isconfigured to read and execute the program instructions from the memorymedium, where the program instructions are executable to implement anyof the various method embodiments described herein (or, any combinationof the method embodiments described herein, or, any subset of any of themethod embodiments described herein, or, any combination of suchsubsets). The device may be realized in any of various forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

What is claimed is:
 1. A method, comprising: by a user equipment device(UE): communicating with a base station using a first bandwidth part(BWP) as an active BWP in a connected mode discontinuous reception(CDRX) communication session; determining that a first timer hasexperienced a status change; and switching a first search space tomonitor and a periodicity of monitoring the first search space in thefirst BWP based at least in part on the determination that the firsttimer has experienced the status change.
 2. The method of claim 1,wherein the first timer is an inactivity timer, wherein the statuschange comprises an initiation of the inactivity timer, and wherein thefirst search space is switched to a search space with enhancedmonitoring parameters.
 3. The method of claim 1, wherein the first timeris an inactivity timer, wherein the status change comprises anexpiration of the inactivity timer, and wherein the first search spaceis switched to a search space with power saving parameters.
 4. Themethod of claim 3, the method further comprising: determining that aretransmission timer is running when the inactivity timer expires, andwherein switching the first search space to monitor and the periodicityof monitoring the first search space is further based at least in parton the determination that the retransmission timer is running when theinactivity timer expires.
 5. The method of claim 1, the method furthercomprising: subsequent to switching the first search space to monitorand the periodicity of monitoring the first search space, determiningthat a second timer has expired; and transitioning the UE to a DRX sleepstate based at least in part on the determination that the second timerhas expired.
 6. The method of claim 1, the method further comprising: bythe UE: when the first BWP is used as the active BWP, continuouslymonitoring a physical downlink control channel (PDCCH); and switchingfrom continuously monitoring the PDCCH to periodically monitoring thePDCCH based at least in part on the determination that the first timerhas experienced the status change.
 7. The method of claim 1, the methodfurther comprising: based at least in part on the determination that thefirst timer has experienced the status change, switching a controlresource set (CORESET) associated with the CDRX communication session.8. The method of claim 7, wherein switching the CORESET associated withthe CDRX communication session comprises switching a monitoring durationof a physical downlink control channel (PDCCH).
 9. The method of claim1, wherein communicating with the base station using the first BWP asthe active BWP in the CDRX communication session is performed inresponse to detection by the UE of initiation of an on-duration timer.10. The method of claim 1, the method further comprising: by the UE:transmitting an uplink message to the base station and monitoring for ahybrid automatic repeat request (HARD) message associated with thetransmitted uplink message while communicating with the base stationusing the first BWP as the active BWP, wherein said switching the firstsearch space to monitor and the periodicity of monitoring the firstsearch space occurs before the UE receives the HARQ message.
 11. Themethod of claim 1, wherein the first timer experiencing the statuschange is associated with light traffic of the CDRX communicationsession, and wherein the first search space comprises a power savingsearch space.
 12. The method of claim 1, wherein the first timerexperiencing the status change is associated with heavy traffic of theCDRX communication session, and wherein the first search space comprisesan enhanced monitoring search space.
 13. A user equipment device (UE),comprising: an antenna; a radio coupled to the antenna; and a processingelement coupled to the radio; wherein the UE is configured to:communicate with a base station using a first bandwidth part (BWP) as anactive BWP in a connected mode discontinuous reception (CDRX)communication session; determine that a first timer has experienced astatus change; and switch a first search space to monitor and aperiodicity of monitoring the first search space in the first BWP basedat least in part on the determination that the first timer hasexperienced the status change.
 14. The UE of claim 13, wherein thestatus change of the first timer is associated with light traffic of theCDRX communication session, and wherein the first search space comprisesa power saving search space.
 15. The UE of claim 13, wherein the statuschange of the first timer is associated with heavy traffic of the CDRXcommunication session, and wherein the first search space comprises anenhanced monitoring search space.
 16. An apparatus, comprising: aprocessor configured to cause a user equipment device (UE) to:communicate with a base station using a first bandwidth part (BWP) as anactive BWP in a connected mode discontinuous reception (CDRX)communication session; determine that a first timer has experienced astatus change; and switch a first search space to monitor and aperiodicity of monitoring the first search space in the first BWP basedat least in part on the determination that the first timer hasexperienced the status change.
 17. The apparatus of claim 16, whereinthe processor is further configured to cause the UE to: based at leastin part on the determination that the first timer has experienced thestatus change, switch a control resource set (CORESET) associated withthe CDRX communication session, wherein switching the CORESET associatedwith the CDRX communication session comprises switching the monitoringduration of a physical downlink control channel (PDCCH).
 18. Theapparatus of claim 16, wherein the first timer is an inactivity timer,wherein when the status change comprises an initiation of the inactivitytimer, the first search space is switched to a search space withenhanced monitoring parameters, and wherein when the status changecomprises an expiration of the inactivity timer, the first search spaceis switched to a search space with power saving parameters.
 19. Theapparatus of claim 16, wherein the first timer experiencing the statuschange is associated with light traffic of the CDRX communicationsession, and wherein the first search space comprises a power savingsearch space.
 20. The apparatus of claim 16, wherein the first timerexperiencing the status change is associated with heavy traffic of theCDRX communication session, and wherein the first search space comprisesan enhanced monitoring search space.